staging: comedi: usbduxsigma: set *_cmd_running flags before submitting urbs
As pointed out by Ian Abbott, the *_cmd_running flags should be set
before submitting the urbs. There is a possible race condition where
an urb could complete and the flag is checked in the completion
routine before it's set.
Reported-by: Ian Abbott <abbotti@mev.co.uk>
Acked-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/staging/comedi/drivers/usbduxsigma.c b/drivers/staging/comedi/drivers/usbduxsigma.c
index 40eeb8c..1af2354 100644
--- a/drivers/staging/comedi/drivers/usbduxsigma.c
+++ b/drivers/staging/comedi/drivers/usbduxsigma.c
@@ -686,13 +686,14 @@
down(&devpriv->sem);
if (!devpriv->ai_cmd_running) {
+ devpriv->ai_cmd_running = 1;
ret = usbduxsigma_submit_urbs(dev, devpriv->ai_urbs,
devpriv->n_ai_urbs, 1);
if (ret < 0) {
+ devpriv->ai_cmd_running = 0;
up(&devpriv->sem);
return ret;
}
- devpriv->ai_cmd_running = 1;
s->async->inttrig = NULL;
}
up(&devpriv->sem);
@@ -740,14 +741,15 @@
if (cmd->start_src == TRIG_NOW) {
/* enable this acquisition operation */
+ devpriv->ai_cmd_running = 1;
ret = usbduxsigma_submit_urbs(dev, devpriv->ai_urbs,
devpriv->n_ai_urbs, 1);
if (ret < 0) {
+ devpriv->ai_cmd_running = 0;
up(&devpriv->sem);
return ret;
}
s->async->inttrig = NULL;
- devpriv->ai_cmd_running = 1;
} else { /* TRIG_INT */
/* wait for an internal signal and submit the urbs later */
s->async->inttrig = usbduxsigma_ai_inttrig;
@@ -876,13 +878,14 @@
down(&devpriv->sem);
if (!devpriv->ao_cmd_running) {
+ devpriv->ao_cmd_running = 1;
ret = usbduxsigma_submit_urbs(dev, devpriv->ao_urbs,
devpriv->n_ao_urbs, 0);
if (ret < 0) {
+ devpriv->ao_cmd_running = 0;
up(&devpriv->sem);
return ret;
}
- devpriv->ao_cmd_running = 1;
s->async->inttrig = NULL;
}
up(&devpriv->sem);
@@ -1026,14 +1029,15 @@
if (cmd->start_src == TRIG_NOW) {
/* enable this acquisition operation */
+ devpriv->ao_cmd_running = 1;
ret = usbduxsigma_submit_urbs(dev, devpriv->ao_urbs,
devpriv->n_ao_urbs, 0);
if (ret < 0) {
+ devpriv->ao_cmd_running = 0;
up(&devpriv->sem);
return ret;
}
s->async->inttrig = NULL;
- devpriv->ao_cmd_running = 1;
} else { /* TRIG_INT */
/* wait for an internal signal and submit the urbs later */
s->async->inttrig = usbduxsigma_ao_inttrig;
@@ -1237,10 +1241,12 @@
memset(devpriv->pwm_urb->transfer_buffer, 0, devpriv->pwm_buf_sz);
- ret = usbduxsigma_submit_pwm_urb(dev);
- if (ret < 0)
- return ret;
devpriv->pwm_cmd_running = 1;
+ ret = usbduxsigma_submit_pwm_urb(dev);
+ if (ret < 0) {
+ devpriv->pwm_cmd_running = 0;
+ return ret;
+ }
return 0;
}